As of version 1.3.5-pre1 of Xamarin.Forms, there doesn't seem to be a way to swipe a TabbedPage on Android out of the box.

I first thought I could add the gesture via a GestureListener in a Custom Renderer, however this causes issues when trying to swipe while showing a full screen button or ListView, as these two controls consume the Gestures, so this wasn't an option.

I then had an idea about combining a CarouselPage and TabbedPage, hence this post.

This is very convoluted and will not perform very well when used in complex UI layouts, but it might be useful.

First the XAML :-

As you can see this layout won't work for Windows Phone and I haven't tested this on iOS however I am only really targeting Android at the moment.